Add production WSGI server - Flask dev server unsuitable for production load

This adds a complete production deployment setup using Gunicorn as the WSGI server, replacing Flask's development server.

Key components:
- Gunicorn configuration with optimized worker settings
- Support for sync, threaded, and async (gevent) workers
- Automatic worker recycling to prevent memory leaks
- Increased timeouts for audio processing
- Production-ready logging and monitoring

Deployment options:
1. Docker/Docker Compose for containerized deployment
2. Systemd service for traditional deployment
3. Nginx reverse proxy configuration
4. SSL/TLS support

Production features:
- wsgi.py entry point for WSGI servers
- gunicorn_config.py with production settings
- Dockerfile with multi-stage build
- docker-compose.yml with full stack (Redis, PostgreSQL)
- nginx.conf with caching and security headers
- systemd service with security hardening
- deploy.sh automated deployment script

Configuration:
- .env.production template with all settings
- Support for environment-based configuration
- Separate requirements-prod.txt
- Prometheus metrics endpoint (/metrics)

Monitoring:
- Health check endpoints for liveness/readiness
- Prometheus-compatible metrics
- Structured logging
- Memory usage tracking
- Request counting

Security:
- Non-root user in Docker
- Systemd security restrictions
- Nginx security headers
- File permission hardening
- Resource limits

Documentation:
- Comprehensive PRODUCTION_DEPLOYMENT.md
- Scaling strategies
- Performance tuning guide
- Troubleshooting section

Also fixed memory_manager.py GC stats collection error.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

requirements-prod.txt

@@ -0,0 +1,27 @@
+# Production requirements for Talk2Me
+# Includes base requirements plus production WSGI server
+
+# Include base requirements
+-r requirements.txt
+
+# Production WSGI server
+gunicorn==21.2.0
+
+# Async workers (optional, for better concurrency)
+gevent==23.9.1
+greenlet==3.0.1
+
+# Production monitoring
+prometheus-client==0.19.0
+
+# Production caching (optional)
+redis==5.0.1
+hiredis==2.3.2
+
+# Database for production (optional, for session storage)
+psycopg2-binary==2.9.9
+SQLAlchemy==2.0.23
+
+# Additional production utilities
+python-json-logger==2.0.7  # JSON logging
+sentry-sdk[flask]==1.39.1  # Error tracking (optional)